Playing a little game [Free art!]

I want to do free art for people but I also want to have fun doing it so we're making it a little game. Below I have categories and you are to guess my favourite song. You may  guess from one category only. I will tell you if you are right or wrong. If you are wrong I will hide your comment and you are welcome to guess again for the same category or a different category.
Artwork will vary, if you guess an easy song [I will categorize them] then you will just get a small headshot. If you can get the harder sections then you might get a full coloured body or even a full blown.
Have fun! If your not into VOCALOID look into my deviations for hints [journals too!]

Favourite Hatsune Miku song: 'Tell Your World' guessed by Iavui
Favourite Hatsune Miku APPEND song: [Very Difficult]
Favourite Kagamine Len Songs: 'Monochrome Baku Eater' guessed by Vixenkiba -- There is still one more!
Favourite Kagamine Rin Song: 'Kokoro' guessed by jay-birds
Favourite Kagamine Duet: 'Trick and Treat' guessed by inuCHIEF
Favourite Kagamine ENGLISH: 'Starstruck' guessed by samaeIis
Favourite Megurine Luka song: [Normal]
Favourite KAITO song: [Easy]
Favourite MEIKO song: [Easy]
Favourite V FLOWER song: [Normal]
Favourite Miku and Luka Duet: 'Worlds End Dancehall' guessed by MentalClockWork
Favourite VOCALOID song series: [Normal]
Favourite VOCALOID All Stars cover: [Normal]
Favourite VOCALOID 10 song: [Very Difficult]
The name of my UTAUloid: Kikoeru Akiko guessed right by Iavui

If its guessed I will put who guessed it -- I expect no one to do this... or maybe people will because free art xD